package com.qianfeng.web.filter;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.qianfeng.entity.User;

public class BackLoginFilter implements Filter {

    public BackLoginFilter() {
    }

	public void destroy() {
	}

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse resp = (HttpServletResponse) response;
		User user = (User) req.getSession().getAttribute("BACK_LOGIN_USER");
		if(user==null){
			resp.getWriter().write("<script>alert('你还没登陆，请先登陆');location.href='../backLogin.jsp'</script>'");
		}else{
			chain.doFilter(req, resp);
		}
	}

	
	public void init(FilterConfig fConfig) throws ServletException {
	}

}
